Safety-stop for elevators.



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PATBNTED APR. 28, 1908. K. WISNIEWSKI L A. MATLAK. SAFETY STOPFOB. ELEVATORSv APPLIGATION FILED was, 1907.

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SAFETY STOP FOR BLEVATORS.

APP'LIOATIoN FILED AUG. 5, 1907.

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KASIMIR WISNIEWSKI AND ANTON MATLAK, OF CHICAGO, ILLINOIS.

SAFETY-STOP FOR ELE VATORS.

Specification of Letters Patent.

Patented .April 28, 1908.

Application filed August 5, 1907. Serial No. 387,087.

To all whom it may concern.'

Be it known that we, KAsIMIR VIsNIEwsKI and ANTON MATLAK, subjects of the Empire of Russia and Empire of Austria-Hungary, respectively, and residents of Chicago, in the county of Cook and State of lllinois, have invented certain new and useful Improvements in Safety-Stops for Elevators, of which the following is a specication.

This invention relates to that class of automatic safety stops for elevator cabs in which aseries of safety pawls upon the cab are automatically forced into engagement with vertical guide racks in the elevator well, on the breakage of the lifting ropes. And the present improvement has for its object to provide a simple and efficient structural arrangement and combination of parts in which the series of safety pawls are forced into holding engagement with the vertical guide racks upon the breakage of any one of the multi le ropes by which the elevator cab is usual y raised and lowered, all as will hereinafter more fully ap ear.

n the accompanying drawings: Figure 1, is a sectional elevation, illustrating the general arrangement of parts in the present invention. F ig. 2, is a detail perspective view of the safety pawls and connections. Fig. 3, is a detail sectional elevation of the safety pawl and their connections in a normal or dormant condition. Fig. 4, is a similar view showing the same in an active or safety condition. Fig. 5 is a detail horizontal section, on line :1J- x Fig. 1.

Similar numerals of reference indicate like parts in the several views.

Referring to the drawings, 1 represents the elevator cage of any usual and ordinary construction, and moving in a vertical elevator well in which the cab is guided by vertically arranged guide racks 2, formed with the usual serrated faces for engagement with the safety awls carried by the cab, as hereinafter more fully set forth. Such guide racks will preferably comprise a central metal portion 2, and side strips 3 of wood, the purpose being to provide a noiseless bearing for the guide brackets 4, of the elevator cab.`

5 and 6 are the multiple lifting ropes by which the elevator cab is raised and lowered, two or four being usually employed in accordance with the size and capacity of the cab. The connection between said ropes and the cab is made yielding by the usual cushion or spring connections 7 as shown in Fig. 1.

and 9 are the safety pawls, usually two in number, and pivoted to the underside of the cab with their free ends adapted-to engage the teeth or serrations of the guide racks 2, in the event of an accident.

10 and 11 are two counterpart sets of lifting levers pivoted on the underside of the elevator ca with each set individual to one of the pair of safety pawls S and 9 aforesaid. Each of said levers is capable of operation independently of the other levers of the set, and to such end one arm of each lever will have bearing against the back of the safety pawl, the said pawl having suflicient width to accommodate the series of lifting levers, while the opposite ends of said levers are connected to individual weights 12 and 13, the tendency of which, when not restrained by means hereinafter described, will be to rock said levers and tilt the safety pawl into locking engagement with a stationary guide rack 2, aforesaid. lt is within the scope of thisA part of the present invention to substitute springs for the weights 12 and 13, in imposing the described downward stress on the lifting levers aforesaid, or to use such springs as an aid to such weights in imposing such downward stress.

14 and 15 are primary holding arms pivoted to brackets 16 and 17 on the up er end of the elevator cab, as shown. Suc hold ing arms are provided with vertical bearing shoes 18 and 19 adapted to rest against the lifting ro es 5 and 6, to be normally held in the raise( condition shown in Fig. 1.

2O and 21 are rope or like exible connections eXtending from the holding arms 14 and 15, around guide sheaves on the elevator cab, and connected to the series of lifting levers 10 and 11 aforesaid, in'opposite relation to the weights 12 and 13, and so as to maintain said weights in a dormant condition.

A material part of the present invention comprises means whereby either of the above described flexible connections 20 and 21 is. adapted to simultaneously operate the pair of opposed safety pawls S and 9, so that with the parting of any one of the lifting ropes 5 and 6, the safety mechanism of the present construction will be brought into immediate and full action, and to such end each flexible connection 2O or 21 will have a branch flexin ble connection 23 or 24 extending around sheaves on the elevator cab and connected to a lifting lever at the opposite side of the elevator cab as shown. With such arrangement the number of lifting levers l0 and l1 will be twice that of the holding arms 14 and 15, and flexible connections 20 and 2l, and so that where two lifting ropes 5 and 6 are employed there will be a corresponding number of holding arms and flexible connections and a total of four lifting levers l() and ll. In like manner, with an increase in the number of lifting ropes a corresponding increasel will be made in the number of said parts.

In Fig. 2, is shown an arrangement of parts where four lifting ropes are employed, and necessitating four holding arms, four flexible connections and eight lifting levers, while Figs. l, 3 and 4, would illustrate the arrangement in which two lifting ropes are used, with the corresponding reduction in the number of the above enumerated parts.

Having thus fully described our said invention what we claim as new and desire to secure by Letters Patent is l. A safety stop for elevators, comprising in combination, an elevator cab, vertical guide racks for said cab, a pair of safety pawls adapted to engage said guide racks, a series of lifting levers common to each safety pawl, and multiple means controlled by the ifting ropes of the cab and comprising in l part flexible connections branched at one end and connected to individual pairs of levers aforesaid, substantially as set forth.

2. A safety stop for elevators, comprising in combination, an elevator cab, verticalil guide racks for said cab, a pair of safety pawls adapted to engage said guide racks, a series of lifting levers common to each safety pawl, and multiple controlling means comprising a series of holding arms provided with vertical shoes adapted to bear upon and be supported by the lifting ropes of the cab, and a series of flexible connections attached at one end `to said holding arms, the other end of said flexible connections being branched and connected to individualvpairs of the lifting levers aforesaid, substantially as set forth.

Signed at Chicago, Illinois, this 29th day of July, 1.907.

KASIMIR WISNIEVSKI. ANTON MATLAK. Vitnesses:

ROBERT BURNs, JOHN SKIKIEWICZ. 

